Wiring a relay to trigger when Google Doorbell (Battery) is pressed

[dr_harika]

Hi, I have an existing doorbell system (KOKOM) which is connected to various gate / door latches and internal monitors bult into the walls of my house in different locations which i use so i want to retain the existing doorbell system and add the google doorbell for smart features mainly for when i am not home. 

The button on my existing doorbell  is just a momentary switch and I have created a new facia which retains the existing camera, but removes the button. The aim is to trigger this button from the google doorbell when pressed using the "ring existing chime" feature. 

I have an 18V AC 500mA transformer to power the google, and i have drawn up a schematic using a rectifier which i think will work but am seeking any advice on sizing the resistor or other circuitry to be able to trigger a relay. Thanks for any advice. 

[dr_harika]

For anyone wanting a solution the original post worked, but i changed to a 82ohm 5W resistor. 
See my other thread on a more technical forum:
https://www.eevblog.com/forum/beginners/connect-relay-to-google-doorbell

[EmersonB]

Hello dr_harika,

Thanks for reaching out here in the Community and we appreciate you sharing here the steps you've done. Let us know if you have more questions in mind. 

Regards,

Emerson

[EmersonB]

Hi dr_harika,

I wanted to follow up and see if you are still in need of any help. Please let me know if you are still having any concerns or questions from here, as I would be happy to take a closer look and assist you further.
  
Best,
Emerson

[EmersonB]

Hey dr_harika,

Just one final check in here since activity has slowed down. We'll be locking the thread in the next 24 hours, but if you still need help, we would be happy to keep it open. If there's more we can do, just let us know.

Thanks,

Emerson